Centerless grinder infeed workrest and ejector mechanism



G. L. GROVE Jan. 8, 1963 CENTERLESS GRINDER INFEED WORKREST AND EJECTOR MECHANISM 5 Sheets-Sheet 2 Filed. April 25, 1960 G. L. GROVE Jan.. 8, 1963 CENTERLESS GRINDER INF'EED WORKREST AND EJECTOR MECHANISM E 1 HWRH mw m m WR E a maw N m.. w 8 mL /M m n Nh m QJ vv M 7.. T m Q 1 J M w/m n! O O IJ Q \o\ .EJE K .AfNmh Q www M ,fr f A .M/ Q 7 (L 8 Q s Q m m l Il .i E@ I w MWIJHVM o QN o @E l) w NQ. .mmm n 5.. my Il I M .vm m NN E HN w 422// i M m I 7 4 F m6 H w Jan. 8, 1963 G. L. GRQVE 3,071,898

CENTERLESS GRINDER INF'EED WORKREST AND EJECTOR MECHANSM Filed April 25, 1960 s sheets-sheet s INVENTOR. 650/965 L. GROVE l /fa 7AM HTTORNEYS United States Patent 3,071,898 Patented Jan. 8, 1963 hce This invention relates to a workrest and work-ejector mechanism used on a centerless grinding machine.

Centerless grinding is usually done on a large lot basis but there is an expanding use of the centerless operation in job shops for small lot jobs. Set-up time is an. 1mportant factor in large lot operation, but in small lot jobs, it becomes a critical factor. Any advantages which a machine may have that result in time saved during set-up of the machine are particularly significant. Centerless grinding operations have always required considerable non-productive time in set-up of a new job. In the usual case, the set-up man makes several trips from the front to the rear of the machine and back again to the front in order to perfect the set-up since machine controls and machine attachments for handling the workpieces are not accessible from one operating position. In addition, due to the machine configuration and the location of the workpiece ejector used for infeed operations at the rear of the grinding area between the grinding and regulating wheels, the working space for set-up is limited. In positioning the ejector, the set-up man usually holds the mechanism in place in the limited space available while fixing it on the workrest. The mechanism is unwieldly and extra care is necessary to prevent it from dropping on fingers or hands while it is being positioned and clamped on the workrest. This extra care requires additional nonproductive time as does the ineicient movement of the set-up man from front to rear of the machine.

An object of this invention is to provide a workrest .and ejector mechanism which is easily set-up from the front as well as the rear of the grinding machine.

Another object is to provide a self-supporting ejector unit that is easily positioned.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof, and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claim, without departing from or exceeding the spirit of the invention.

A mechanism constructed in accordance with the preferred form of this invention has clamping means to hold the ejector unit in correct relation to the workrest. The clamping means are conveniently operable from the front and the rear of the machine, and, when the clamping means are released, the ejector mechanism is supported by a positioning screw. The ejector mechanism can be easily positioned relative to the workrest in accordance with the size of the workpiece to be ground and then reclamped in a minimum of time.

A clear understanding of this invention is apparent from the following detailed description and the attached drawings wherein:

FIG. l is an elevational view of the workrest and ejector mechanism from the regulating wheel position of a centerless grinder.

FIG. 2 is a section view of the ejector mechanism and the rear end of the workrest, taken on line 2-2 of FIG. 5.

FIG. 3 is a section of the lower stud along line 3-3 of FIG. l.

IGA is a section of the ejector mechanism on line 4 4 of FIG. 2 with an adjusted position of the ejector mechanism shown in phantom.

FIGS. S and 6 are front views of the workrest with workpieces of different size thereon..

In FIG. l the workrest and ejector mechanism are shown in place on a centerless grinding machine cross slide 12 between the grinding wheel 11 and regulating wheel (not shown in FIG. l). The front of the machine is at the left and workpieces are fed into and removed from the grinding area at the front of the machine, the

. machine being arranged for an infeed grinding operation.

The workrest is comprised of a base member 10 which is located on and bolted to the machine cross slide 12. The base receives a workrest blade 14 on which the workpiece 16 (FIG. 2) rests during the grinding operation. The base includes a face plate 18 connected at one end thereof. The ejector mechanism 20 is received on the face plate 18. As shown by FIG. 2, the ejector mechanism is comprised of the activating assembly carried by the ejector chassis 22. The activating assembly comprises a ram 24 against which a workpiece is fed during the grinding operation, the ram acting as a feed stop. At the end of each grind cycle, the ram is moved toward the front of the machine to eject the workpiece. The ram is moved forward by lever 26 which engages with a pivotal shoe 28 attached to collar 30 xed to the ram. Lever 26 is operated by plunger 32 of the hydraulic motor 34 which is controlled by the solenoid valve 36 and solenoid 38. The ram also may be moved forward by push rod 40 activated by manual lever 42 (FIGS. 5, 6)

l at the front of the machine and connected to push rod 4i) by linkage 44 (FIG. 1). The spring 46 returns the ram to the `rear position after the forward stroke, that stroke signaled by limit switch 48 in power operation. The ejector chassis 22 which carries the ejector mechanism is positioned on clamped to the face plate 18 by stud and nut arrangements 50 and 52 (FIG. 1).

FIG. 2 reveals that the upper stud 54 received in the face plate 18 and ejector chassis 22 loosely receives strap clamp 56 and washer 58 and has upper front nut 60 and upper rear nut 62 in threaded engagement with its ends. FIG. 3 shows the lower stud 64, received in the face plate 18 and ejector chassis 22, loosely receives washer 66 and has lower front nut 68 and lower rear nut 70 in engagement with its ends. The upper and lower studs are similarly received in the face plate. The stud lis longitudinally movable in the face plate but not rotatable. The upper and lower studs have flats 71, 72, respectively. These ats are engaged by -a set screw 74 which is tight enough to prevent rotation, but not to prevent longitudinal movement. Therefore, as one nut is tightened and moved toward the other nut on .a stud, a clamping eifect between face plate and ejector chassis is achieved, the nuts being the clamping means, and the ejector chassis and the face plate, being located between the front and rear nuts, are clamped together. The nuts of the lower stud are not conventional nuts. The lower front nut has a -threaded portion 76, an extension 78 through the grinding area and a head portion 80 located in va recess 82 in the base 10 ('FIG. l) at the front of the machine. The lower rear nut 70 is elongated land extends to the rear of the grinding machine (FIG. l). This construction provides for convenient access to the ejector mechanism clamping means, the upper stud and nuts being exposed above the grinding area and ejector mechanism.

The ejector chassis is unclamped when one of each pair of upper and lower nuts is loosened relative to the other. f

In the unclamped condition, the ejector chassis is supported by vertical positioning screw 84, FIG. 2, which is in threaded engagement with the overhanging portion 86 of the chassis and received at one end against the top of the face plate 18. The vertical positioning screw may be used to raise or lower the ejector mechanism relative to the face plate and any change due to workpiece requirements may be easily effected. Reference is made to FIG. 4 in which the ejector chassis 22 is shown in section from the rear of the machine. FIG. 4 shows the manner in which the studs are received through the ejector chassis to provide for movement lthrough a range of positions- The upper stud 54 is loosely received through an upper clearance opening 88 in the chassis while the lower stud 64 is loosely received in a lower vertical clearance slot 90. The vertical movement of the chassis 22 relative to the face plate is limited by these two clearances. At the same time, the chassis is pivotal around the lower stud within limits imposed by the upper clearance opening since there is a lateral resriction imposed only at the lower stud due to the shape of that clearance open-ing. The phantom view in FIG. 4 is illustrative of the movement available, that view showing both vertical and lateral displacement of the ram 24.

In FIGS. 5 and 6 workpieces 92 'and 94, respectively, of different size, are shown. In order to change the set up of .the machine from operation on one of these workpieces to the other, -all adjustment of the ejector relative to the workrest can be made from the operators position in front of the machine. The upper stud and nut arrangement 50 is exposed to the set-up man. The lower stud and nut arrangement 52 is in convenient location as shown in FIG. 1. The grinding area bounded by grinding wheel 11 and regulating wheel 100 does not interfere with the set-up. When unclamped, the ejector supports itself on the positioning screw 84 till the proper adjustment is made and the unit is reclamped,

What is claimed is:

In a centerless grinding machine having a wor-krest blade for supporting a workpiece in the grinding area and an ejector mechanism for removing said workpiece from said area, the combination of a base received on the grinding machine below the grinding area adapted to support said workrest blade, a vertical face plate lixcd to the rear end of said base having an upper longitudinally movable stud extending therethrough above the workrest blade and ejector mechanism for access from either side of said plate, said face plate having a lower longitudinally movable stud extending therethrough below the workrest blade and ejector mechanism, a front and rear nut threadedly received respectively on each end of each of said studs, the nuts received on the lower stud extending forwardly and rearwardly, respectively, for access from the front and rear of the machine, .an ejector chassis member adapted to support said ejector mechanism received aga-inst said face plate, said chassis member having a vertical clearance slot to receive said lower stud 4and a clearance opening to receive said upper stud -to permit vertical positioning of said chassis member on said face plate and to permit pivotal positioning thereof about said lower stud when one of said nuts on each stud 4is loosened, and a vertically extending screw threadedly received in said chassis member and adapted to engage the ltop of said face plate to support the chassis member and effect vertical position-ing thereof when one of said nuts on each stud is loosened.

References Cited in the tile of this patent UNITED STATES PATENTS 1,585,982 Heim May 25, 1926 2,364,855 Kampstad etal. Dec. 12, 1944 2,472,707 Jones et al. June 7, 1949 2,655,773 Wetterborg Oct. 20, 1953 

